The structure of a sulfated galactan from Porphyra haitanensis and its in vivo antioxidant activity Original Research Article

The sulfated galactan fraction F1 isolated from the red seaweed, Porphyra haitanensis, showed typical porphyran structure. It has a linear backbone of alternating 3-linked β-d-galactosyl units and 4-linked α-l-galactosyl 6-sulfate and 3,6-anhydro-α-l-galactosyl units. The l-residues are mainly composed of α-l-galactosyl 6-sulfate units, and the 3,6-anhydrogalactosyl units are minor. Partial methylation occurred at the C-6 position of the d-galactosyl units and at the C-2 position of the 3,6-anhydro-α-l-galactosyl units. Intraperitoneal administration of F1 significantly decreased the lipid peroxidation in aging mice. F1 treatment increased the total antioxidant capacity and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in aging mice. The results indicated that F1 had significant in vivo antioxidant activity.